I have a 2002 chrysler Sebring limited convertible 2.7Lv6 ..Ac problem

Here is what’s going on you guys I have an 2002 chrysler Sebring limited convertible jxi 2 door 2.7Lv6 Dohc... My Ac is full of Freon when it is on it will freeze you out of the car . The heater works fine as well . Sometimes it seem to blow not as cold at all than the other times ice cold . We check the Freon it is full . The two fans are coming on all the time and the compressor is coming on . I check for any debris in the intake no debris . We looked at the condenser no bugs or dirt because I put a car cover on it . The fan belt looks tight . The hoses has no leaks . Inside the car the air or heat will move to all the compartments . Now the hvac climate control I try to reset and I can not it will not reset . The temperature gauge the above it that tells north south and degree . Sometimes it will show it , the other day it was upside down and now it do not come on . We did switch the computer sysytem a few years back and now that I think of it I am not sure if they were suppose to program or cal rated with the new system but it has not ran like it used to . It does not matter how hot it gets I never had my ac get cold than not so cold and when I did try to rest it it did go back to cold but I never did see it show up on the speed odometer the Ac 000 I think I saw this on You tube . Let me ask you this I am not sure if this car has a cabin filter if so where are they ? Do you think this is the hvac climate control ? Or what do you think ? I am not a mechanic but had to learn if I did not want to pay rediculouse prices . I also know some men who also been teaching me but we are all puzzled . Every time I will say I am bring you to the mechanic it looks like the car ac runs ok and no one can find anything but when it decides I will not blow cold air you will sweat in this car than all in a sudden freezing cold . I also notice it you run it full blast it is not as cold or sometimes warm but if you turn the knob and put it on a lower setting it is cold again . Also sometimes it will do this at the hottest part of the day 12-6 pm but like today it did not it stayed cold . We also thought it might be the ac refrigator temperature sensor switch but the hvac climate control i am thing because I can not reset it . We did try a while back to replace the hvac climate control than no air came out but we did not know if it needs to be progrAm or something so we put the old one back in and I think this is the orginal hvac climate control . The temperature gauge above it also had crazy reading , up side down an now it was blank but still cold air was coming . Please try to help if you know . It will not act up at the mechanic shop .